In laying out the foundations of structures, and particularly residential structures and related structures, it is important that the foundation be square, or otherwise have a geometry precisely matching a desired geometry for the foundation and for the structure. Most commonly, corners of the foundation are square corners measuring 90°. While numerous tools are in existence for assisting in the layout of 90° “square” corners, each of these tools has certain drawbacks.
“Carpenter's square” type devices are known which are typically in the form of a large “L” formed of rigid metal or other material. While these “carpenter's squares” do precisely measure 90°, the legs of the carpenter's square are not particularly long, typically no longer than two or three feet. Even the smallest structures will typically extend significantly beyond the ends of the legs of a carpenter's square. Hence, the foundation must be carefully extended linearly beyond the carpenter's square so that a properly square corner is provided. Even when a carpenter's square is precisely utilized, most commonly some degree of error results when the sides of the structure adjacent the square corner are extended.
Surveying equipment can be utilized, such as a transit, to precisely lay out the corners of the structure where desired. Typically however, such surveying tools are most effective when a team of surveyors can work together. When a single worker wishes to lay out the foundation alone, use of such surveying equipment involves numerous trips back and forth between the surveyor's transit and the location being measured. Also, such surveying equipment requires a certain level of surveying skill beneficially practiced by surveying professionals, rather than less skilled users.
Another option is to use some form of protractor to measure the 90° angle or other angle of the corner. Even a large protractor will have the same deficiency as the carpenter's square, in that when the sides of the structure adjacent the corner are extended, they will rarely precisely have the measurement desired.
Often foundation builders will utilize geometric techniques to measure out the sides of form boards for use in pouring cementitious material to form the foundation, so that the proper 90° is provided. For instance, it is known that a triangle having a first leg a multiple of three feet long, a second leg a multiple of four feet long and a hypotenuse leg a multiple of five feet long (i.e. 3 ft.×4 ft.×5 ft. or 6 ft.×8 ft.×10 ft.) will have a corner between the first leg and the second leg measuring precisely 90°. While this technique is effective, it requires a significant amount of time to implement, significantly delaying the process of laying out and forming the foundation of the structure.
Specifically, after identifying a position for the tip of the square corner, a first side adjacent the corner is provided with a reference stake or other structure three feet (or six feet, nine feet, etc.) away from the tip of the corner and in the desired direction. Once this first side adjacent the corner has been positioned, the second side is laid out in a position which appears approximately 90° away from the first side to be located adjacent the corner. This second side is marked at a distance four feet (or eight feet, twelve feet, etc.) away from the tip of the corner. A measurement is then taken from the first reference point at the end of the first side to the second reference point at the end of the second side. If it measures precisely five feet (or ten feet, fifteen feet, etc.) then the corner is precisely 90°. However, if it is slightly greater than or less than five feet (or ten feet, fifteen feet, etc.) the second reference point and second side must be adjusted, such as by trial and error. While this technique is generally effective, it takes a significant amount of time to implement in practice.
Accordingly, a need exists for quickly and easily precisely laying out foundations for structures which are precisely square or otherwise having properly angled corners.